asme换热器复证中一个问题

ace

tomcat711说的有道理，所以我在9楼说加垫板可能就是AI的个人习惯。但是楼主所说的手孔，对封闭缝焊接没有什么帮助，最多焊完后通过手孔看一下

wj668993672

问过AI，说是单面焊双面成型的话，要么能全射线探伤，要么能通过人孔或者手孔在背面可以看到

加油

如果要带永久性垫板，那么接头系数不是不属于UW-12 类型1了吗？相应的接头系数不是也需要修改了吗？对于DN800的直径，没有人孔应该可以双壁透照做RT吧？

qimmyzhang

要满足焊缝系数的要求吧，我觉的

1csss

可能是左后一道环缝无法目视检测，所以你要加衬垫

fredwang

UW-35 FINISHED LONGITUDINAL AND
CIRCUMFERENTIAL JOINTS (a) Butt welded joints shall have complete penetration and full fusion；
UW-12
(1)Butt joints as attained by double‐welding or by other means which will obtain the same quality of deposited weld metal on the inside
and outside weld surfaces to agree with the requirements of UW-35. Welds using metal backing strips which remain in place are excluded.

SPOT RT，手孔如果不能保证看到合拢缝全部内侧，则不能认为符合UW-35的要求，带衬环更为稳妥！